解调: g(O) coS Oo相乘()omon g(t) 低通 CoSO go(t)=[g(t)cos aot]cos oot =g(t)(1+cos20t) 2 g(t)+g(t)cos loot 2 2 G)=G()+[G(0+200)+G(0-2006 解调： g(t)cos0 t 相乘 t 0 cos 低通 ( ) 0 g t g(t) g t g t t g t t g t g t t t 0 0 0 0 0 ( ) cos 2 2 1 ( ) 2 1 ( )(1 cos 2 ) 2 1 ( ) [ ( ) cos ]cos     = + = + = [ ( 2 ) ( 2 )] 4 1 ( ) 2 1 ( ) G0  = G  + G  + 0 + G  − 0 − m  m